Helena Hepola

Milk feeding systems for dairy calves in groups: effects on feed intake, growth and health

Abstract The number of calves reared in groups is increasing. If the calves are reared in small groups, they can be fed from buckets with or without teats or from small containers connected with teats via tubes. In big groups the simplest solution is ad libitum feeding from the containers with teats or from automatic feeders. Recently, the computer-controlled milk feeding system has become more common. Good production results have been obtained in large groups with ad libitum feeding of milk but there can be problems, especially, when weaning the calves. When calves obtain milk ad libitum they usually eat little concentrates and this can lead to post weaning lag in growth. One disadvantage of ad libitum feeding is the economic feasibility of this system compared to restricted feeding, because milk amounts drunk are so big. The risk of infection is higher in groups, whatever the milk feeding method is, and this can lead to health problems in big groups. Not many experiments about the effect of the computer-controlled milk feeding system on feed intake, growth, and health of dairy calves have been carried out, especially with big groups of 25–30 calves. According to farm questionnaires especially the incidence of respiratory disease has been increasing when group feeding with the computer-controlled milk feeding systems has been installed. More knowledge is needed about problems with big calves disturbing milk intake of smaller calves, the best age and method to introduce the calves to the equipment, and detection of illnesses according to the intake data.

The formation of preferential relationships at early age in cattle.

Calves can develop long-lasting social relationships with peers. We examined the strength of the relationships between calves according to the time they had been together. Twenty-four female dairy calves were assigned to six groups of four animals (Type-1 partners) at 0.5 month of age. At 3.5 months of age, they were mixed with other calves (Type-2 partners) to form groups of 14. Type-3 partners were calves added to the experimental groups after 5.25 months. The calves stayed together until 1.5 years of age. Social preferences between the three partner types were examined in a Y-maze, and the position and activity of animals in the barn and pasture were followed in three periods. Behavioural synchrony, distance between animals, proximity and nearest neighbour were analysed. The calves more frequently butted Type-3 than Type-1 partners in the Y-maze (P<0.05). They spent more time in proximity to Type-1 partners, and these were more often the nearest neighbours than other partners (P<0.001). Synchrony and distance between animals were greater at pasture than in the barn (P<0.01). Calves seem to form preferential relationships before 3.5 months of age. Keeping cattle together from an early age seems beneficial for them.

Sufficiency of the energy and protein standards for lactation of adult multiparous Finnish Landrace ewes

Abstract Thirty-six Finnish Landrace ewes (2 to 5 years old) were used to study the adequacy of Finnish energy and protein standards for lactation. Animals nursing either singles, twins or triplets were milked by machine three times a week for 8 weeks. To meet the energy and protein requirements for milk production, the ewes were fed 0.4 fattening feed units (FFU = 0.7 kg starch equivalent) ± 10% and 60 g of digestible crude protein (DCP) ± 10% per suckling lamb. The levels (L, low; S, standard; H, high) were incorporated in the concentrates. Hay was given ad libitum. Milk yield was estimated during a 4 h period by the oxytocin method. Changing the energy and protein level by ± 10% from the feeding standards did not affect the average milk yield of ewes rearing twins or triplets. However, in the single-suckled ewes the estimated lactation curve of L treatment tended to plateau, with the result that the L ewes produced more milk per lamb than those on S and H treatments after the fourth lactation week. The average 4 h milk yields (and standard deviations) per lamb for single, twin and triplet-suckled ewes on S treatment were 414 (118), 285 (73) and 163 g (32), respectively. The milk fat content for single-suckled S ewes declined faster than did those for L and H ewes while in triplet-suckled ewes the fat decline was larger for L than for S and H ewes. The mean observed protein content of milk was lowest for the H treatment in each rearing type, but only in single and triplet-suckled ewes was there some slight evidence that this did not occur by chance alone. The milk of ewes nursing triplets had a higher lactose content than that of those nursing singles. The ewes on each treatment exhibited a slight loss in live weight during lactation. No marked differences between the feeding groups were noted in solid feed intake or live weights of lambs per pen. The results suggest that the energy and protein standards used in Finland are sufficient for the milk production of adult Finnish Landrace ewes.

Five or eight weeks of restricted suckling: influence on dairy calves’ feed intake, growth and suckling behaviour

Abstract Concern about welfare and behavioural needs of animals has increased the interest in keeping calf and cow together after parturition. In this experiment six calves suckled their dams twice a day for five weeks then once a day for three weeks (DAM8). Six calves (DAM5) suckled during five weeks in the same way as calves in DAM8 and were then abruptly weaned. Six calves (TEAT8) were fed the same amount of milk from teat buckets as DAM8. Consumption of dry feed by all calves was low at the age of five weeks. Consequently, the calves abruptly weaned at the age of five weeks lost weight after weaning. Nursing times were quite similar (about 20 min) during the entire suckling period. However, reducing suckling from twice a day to once a day at the age of five weeks increased the frequency of teat changing. In conclusion, total weaning at the age of five weeks from high milk allowance seems not recommendable. Five weeks of twice a day suckling followed by three weeks of once a day suckling is likely to reduce the decline in energy intake and growth following weaning.

A note on overdispersion as an index of behavioural synchrony: a pilot study in dairy cows

We developed a method for studying the synchrony of behaviour based on calculations of overdispersion of a binomial process. The lying behaviour of cows was investigated under two different housing units inside the same barn. The first unit housed 30 cows undergoing conventional milking and the second unit housed 27 cows undergoing automatic milking. The lying behaviour of the cows was observed over 3 weeks in 12 periods of 6 h each. Every 5 min, we counted the number of cows lying down in the cubicles. As external cues, like feeding and conventional milking, can promote synchrony in dairy cows, we expected that cows conventionally milked would show more behavioural synchrony than automatically milked cows. Cows lied down synchronously in both units (overdispersion 1.67, P < 0.01). Lying synchrony tended to be slightly bigger in automatically than in conventionally milked cows (overdispersion 1.76 v. 1.58, P = 0.09), although the proportion of cows lying down was on average greater in conventionally than in automatically milked cows (60.7% v. 45.6%). This suggests that synchronized lying behaviour in cows is a constant phenomenon that depends on social facilitation rather than on external cues. The overdispersion index appears to be a useful tool for studying the synchrony of animal behaviour when observations are made at the group level.